Looking for advice on re-upgrading

[Timonator]

This is on my 1970 Buick GS. Primarily street use but maybe some autocrossing.
My first question is what spindles to go with. Tall or short ? And then what control arms give more positive caster without pushing the spindle outward ?
Right now I have stock control arms and spindles with tall ball joints .

[raustinss]

Speedtechperformance.com...ats spindles and lots of manufacturers have high quality control arms

[UMI Tech]

We (UMI Performance) have high caster arms and track width is unaffected.

The geometry doesn't know whether the distance comes from spindle or ball joints(s). It is difficult to get the amount of height available in a spindle (1.75" extra) with ball joints.

We sell Speedway Motors 2" drop spindles in our higher end kits. Our LeMans is blazing fast and still drives and rides nice on the street.

[email protected]

[Hotwire]

How are you running stock control arms and tall ball joints? I've heard and seen they bind up due to the mounting angle of the stock arms.

I'm running SPC fully adjustable upper arms and ebay tubular lowers, CPP 2" lowering spindles, and 0.9" taller upper and 0.5" taller lower balljoints, they're working great.

Someone made mention of these on another thread, wish I'd known about them when putting together my suspension: https://www.speedwaymotors.com/G-Comp-2-Inch-Drop-Performance-Spindles-for-GM-A-F-X-Body-Muscle-Cars,80737.html

[Hotwire]

We (UMI Performance) have high caster arms and track width is unaffected.

The geometry doesn't know whether the distance comes from spindle or ball joints(s). It is difficult to get the amount of height available in a spindle (1.75" extra) with ball joints.

We sell Speedway Motors 2" drop spindles in our higher end kits. Our LeMans is blazing fast and still drives and rides nice on the street.

[email protected]

The LeMans is fast! You can see how it goes vs STOCK 64 Chevelle suspension. Mine was leaning so bad the stock camber was pushing the tires into the wheelwells and smoking the sidewalls.

https://www.youtube.com/watch?v=KojEWB45AUo

[UMI Tech]

The LeMans is fast! You can see how it goes vs STOCK 64 Chevelle suspension. Mine was leaning so bad the stock camber was pushing the tires into the wheelwells and smoking the sidewalls.

https://www.youtube.com/watch?v=KojEWB45AUo

Hey Jeff. Thanks for that video clip! Back when the world was "normal". Car fun with car friends.

[stab6902]

How are you running stock control arms and tall ball joints? I've heard and seen they bind up due to the mounting angle of the stock arms.



I'm running 0.5" taller uppers in an A-body and 0.9" taller uppers in an F-body on stock arms with no issues. Both cars are lowered 2"+ as well. There is definitely some angle on the balljoints, so I'm sure aftermarket arms would be much better. I didn't dig too deep into how much taller you could go; I just went with what others had reported to use without problems. As far as I know the Ridetech Street Grip kits, which are intended for stock control arms, come with 0.5" taller upper ball joints, and I know they sell a ton of those.

[Timonator]

We (UMI Performance) have high caster arms and track width is unaffected.

The geometry doesn't know whether the distance comes from spindle or ball joints(s). It is difficult to get the amount of height available in a spindle (1.75" extra) with ball joints.

We sell Speedway Motors 2" drop spindles in our higher end kits. Our LeMans is blazing fast and still drives and rides nice on the street.

[email protected]

So, are those the control arms that Jeff posted a link to below They are the taller ones ? What control arms, and wheel and tire sizes on your Lemans ?

- - - Updated - - -

Cool video !

[UMI Tech]

Good morning. The LeMans has our #cornermax arms with standard ball joints (due to the tall spindle).

https://www.umiperformance.com/home/product/1964-1972-gm-a-body-tubular-lower-front-a-arms-corner-max-tall-ball-joint/

Our wheels are 18x11x6.26BS and 315/30-18 tires. Front inner fenders removed for clearance.

[Hotwire]

So, are those the control arms that Jeff posted a link to below They are the taller ones ? What control arms, and wheel and tire sizes on your Lemans ?

- - - Updated - - -

Cool video !

Thank you!

Helping Ramey out, this should answer some questions for you:

https://www.umiperformance.com/home/the-gm-a-body-pros-and-cons/

Here's my take on things: GM A-bodies have "short" spindle height from the factory. Meaning the when stock balljoints are secured to stock spindles the pivot point of the balljoints are shorter than the pivot points of the a-arms they're connected to.

You want to have the a-arms parallel to one another so your camber is not affected when the suspension travels through it's arc. The way our factory geometry is, it's a BAD trapezoid. See pic below, this a was a quick illustration I did to help others see the problem. On the left is our factory geometry, red=frame/a-arm bushings, blue = a-arms, orange=stock spindles. On the right is "corrected" geometry, aqua=space needed to correct bad geometry. You can either use a taller spindle to get that height or taller ball joints. Notice the BAD positive camber on the left during compression, no bueno. Notice on the right how there is NO angle change throughout the suspension arc. That's what you want, if not getting negative camber on compression so your front tire tries to bite harder when going into a curve. With stock spindle, taller upper and lower ball joints I'm getting -3 degrees from full droop to full compression.

https://static1.pt-content.com/images/pt/2021/03/51061837443_50d8681852_o-1.jpg (https://flic.kr/p/2kNagiD)a-body_front_suspension (https://flic.kr/p/2kNagiD) by Jeff Bowne (https://www.flickr.com/photos/157865784@N06/), on Flickr

These pictures were taken by Tim King of Lateral G / UMI at the Summit Motorama, same event the video I posted above was from. You can literally see my tires are acting exactly like the diagram above.

https://static1.pt-content.com/images/pt/2021/03/Jeff20Bowne202320of2040_resize_12_zpsbwm-1.jpg

https://static1.pt-content.com/images/pt/2021/03/59522032_10157518448048643_2141282393829-1.jpg

This was yesterday at Caraway Speedway in Sophia, NC blowing a lot of people's minds. I'm on a 255/40/17 cooper zeon rs3-g1 500 treadwear tire keeping up with guys running 200 treadwear tires. I was freaked out by the fast track and took 0 pics/vids. Relying on others that will share theirs with me. Hoping I can get pics/vids from the slalom area, if I do I'll update so you can see the difference in how the car is handling.

https://youtu.be/7fEnTr4lUyY

[Timonator]

Great illustration Jeff, and even cooler pics !
Ramey, I'm looking at your 406502 kit for the front. Do you offer that kit with conventional shocks and springs ? Can I get it without the sway bar ? What would you recommend for rear control arms and springs? It looks like you have quite a few options for rear control arms.

[Hotwire]

Thank you Tim, I think I figured out the sauce on this one and just trying to help others wrap their head around it. My buddies tried to talk me into these mods years ago when we were messing with S10s and I couldn't imagine the factory letting something out the door acting that way. After driving this chevelle and seeing pictures/evidence of it's handling I dove in head first.

Ramey if you could comment on bumpsteer with your arms that would be interesting too.

I'm running 0.5" taller lower balljoints and it's removed 100% bumpsteer. Before, hitting bumps, the steering wheel would try to jerk out of my hands, now I can hit bridge abutments going 80 with a finger on the wheel. The taller lower does lower the front by 0.5" but it's so worth doing them, car drives better than my daily.

Once you get the geometry right, you will blow your mind and others. My rust bucket is like piloting a newer camaro around the track. I'm still running factory style moog springs and KYB gas-a-just shocks! It rides like butter going down the road and handle anything you put at it, freaking aneurysm red swiss army knife.

https://static1.pt-content.com/images/pt/2021/03/1026191735c_resize_89_zpstewokzis-1.jpg

[UMI Tech]

Great illustration Jeff, and even cooler pics !
Ramey, I'm looking at your 406502 kit for the front. Do you offer that kit with conventional shocks and springs ? Can I get it without the sway bar ? What would you recommend for rear control arms and springs? It looks like you have quite a few options for rear control arms.

Hi Tim.

We can mix and match whatever you'd like. I do custom quotes all the time. You can give me a call at 814-376-6000 or email [email protected] and I'm happy to put a package together for you.

Cornermax lower arms are coilover only but we can make cars plenty fast on our conventional springs and standard lower arms.

rw

[UMI Tech]

Thank you Tim, I think I figured out the sauce on this one and just trying to help others wrap their head around it. My buddies tried to talk me into these mods years ago when we were messing with S10s and I couldn't imagine the factory letting something out the door acting that way. After driving this chevelle and seeing pictures/evidence of it's handling I dove in head first.

Ramey if you could comment on bumpsteer with your arms that would be interesting too.

I'm running 0.5" taller lower balljoints and it's removed 100% bumpsteer. Before, hitting bumps, the steering wheel would try to jerk out of my hands, now I can hit bridge abutments going 80 with a finger on the wheel. The taller lower does lower the front by 0.5" but it's so worth doing them, car drives better than my daily.

Once you get the geometry right, you will blow your mind and others. My rust bucket is like piloting a newer camaro around the track. I'm still running factory style moog springs and KYB gas-a-just shocks! It rides like butter going down the road and handle anything you put at it, freaking aneurysm red swiss army knife.

https://static1.pt-content.com/images/pt/2021/03/1026191735c_resize_89_zpstewokzis-1.jpg

Good morning.

The tall lower ball joint sometimes helps bump steer. We've had a few A-bodies where it didn't help at all, most likely due to inconsistencies in the GM tolerances. These frames are all over the place.

Bump steer tends to get worse when we add a bunch of caster, since we're hiking the steering arm way up in the air (due to tilting the spindle back). The bump steer kit lowers the tie rod back down to it's original-ish level. We use a Longacre bump steer gauge to set our cars as we are familiar with those tools since most of us are oval track racers.